REVEALING THE ORIGIN OF BORDEAUX WINES WITH RAW 1D-CHROMATOGRAMS

4-Ethylphenol (EP) in wine is associated with organoleptic defects such as barn and horse sweat odors. The origin of EP is the bioconversion reaction of p-coumaric acid (CA), naturally present in grapes and grape musts by contaminating yeasts of the genus Brettanomyces bruxellensis. Yeast cell walls (YCW) have shown adsorption capacities for different compounds. They could be applied to wines in order to adsorb either CA and/or EP and thus reduce the organoleptic defects caused by the contaminating yeasts.

Infection of grapes (Vitis vinifera) by Botrytis cinerea (grey mould) is a frequent occurrence in vineyards and during prolonged wet and humid conditions can lead to significant detrimental impact on yield and overall quality. Growth of B. cinerea causes oxidisation of phenolic compounds resulting in a loss of colour and formation of a suite of off-flavours and odours in wine made from excessively infected fruit. Apart from wine grapes, developing post-harvest B. cinerea infection in high-value horticultural products during storage, shipment and marketing may cause significant loss in fresh fruits, vegetables and other crops. A rapid and sensitive assessment method to detect, screen and quantify fungal infection would greatly assist viticultural growers and winemakers in determining fruit quality.

The pinking of in white wine is the turning of color from yellow to salmon hue. White wines obtained from certain grape varieties (e.g. Chardonnay, Sauvignon blanc, Riesling, Trebbiano di Lugana) showed to be susceptible to pinking [1] that has been evaluated by an assay providing the addition of hydrogen peroxide. Even if its appearance does not seem to affect the sensory properties [2], strategies are necessary for its removal. Nowadays, the treatment with polyvinylpolipirroline (PVPP) was reported to significantly decrease the pink color [3].

In the last decades the use of bioestimulants in viticulture have been promoted as alternative to conven- tional pesticides. Moreover, as bioestimulants promote the biosynthesis of secondary metabolites in grape berries, several studies had investigated their influence on the accumulation of phenolic com- pounds (Monteiro et al., 2022). However, few studies, so far, are focused on the accumulation of the vo- latile compounds and their impact on the produced wines (Giménez-Bañón et al., 2022; Gomez- Plaza et al., 2012; Ruiz Garcia et al., 2014).
This study was conducted in a single vineyard of white autochthonous grapevine variety Savvatia- no (Vitis vinifera L.) in Muses Valley (Askri, Viotia, Greece). Chitosan (CHT), Abscisic Acid (ABA) and Benzothiadiazole (BTH) were applied.

Smoke impact in wines is caused by a wide range of volatile phenols found in wildfire smoke. These compounds are absorbed and accumulate in berries, where they may also become glycosylated. Both volatile and glycosylated forms eventually end up in wine where they can cause off-flavors, described as “smoky”, “bacon”, “campfire” and “ashtray”, often long-lasting and lingering on the palate. In cases of large wildfire events, economic losses for all wine industry actors can be devastating.